Action Trueing / Blueprinting?

[bboswell]

I have always taken these term pretty much for granted.In some recent study I have found some varied opinions of what “Trueing an Action” consists of.

So, for a Rem 700 action what should be expected when a GS tells you he will true or blueprint your action?

[BURTONboy]

Interested in this as well. I've never really understand exactly what it ment.

[SOLID EAGLE]

In for info

[Slick8]

I believe I understand it better than I can explain it but at it's very basic;

Trueing an Action consist of cutting the action threads to match those of the barrel and squaring them to the action. Then squaring the bolt face to the action and finally lapping the rear of the bolt lugs to the action for a 100% or near 100% lug to action contact point.

I'm sure the pro's can chime in and add to it, but that's the very basics.

IMO, blue printing simply means that you're recording your final measurements after all machine work is completed.

[StrayDog]

This is video 1 of several...

https://www.youtube.com/watch?v=n191F9c1YiQ

[Cajun Blake]

edit: StrayDog beat me to it great post brother




watch this guys videos suar08161991 ... he has 13 part series on truing a Rem 700 action

very informative and you will be surprised when a factory action is chucked up in the lathe


here are videos 1-4 ....



[ame="http://www.youtube.com/watch?v=n191F9c1YiQ"]http://www.youtube.com/watch?v=n191F9c1YiQ[/ame]


[ame="http://www.youtube.com/watch?v=Ny9wZtVbjz0"]http://www.youtube.com/watch?v=Ny9wZtVbjz0[/ame]


[ame="http://www.youtube.com/watch?v=Q1NlIKGO6XM"]http://www.youtube.com/watch?v=Q1NlIKGO6XM[/ame]


[ame="http://www.youtube.com/watch?v=QBrqUk8idtM"]http://www.youtube.com/watch?v=QBrqUk8idtM[/ame]

[cajuntec]

Tagged for later review.
All the best,
Glenn

[Reaper33]

subscribed

[krisw]

I have always wondered too.

[bboswell]

This video points out the very major difference in what many people consider is trueing an action; the cutting of the action threads.

Many GS's simply run a tap through the existing action threads, square the action face and bolt face etc.This really does nothing to true the threads of the action, it simply cleans up the threads and leaves them with the same amount of misalignment to the bore that the factory rifle came with.

Perfect alignment and single tool cutting the action thread oversized in alignment with the centerline is what should be done.

So when a GS tells you he is Trueing or Blueprinting the action or when you are buying a used rifle that has been Blueprinted how do you know exactly what has or has not been left out of the proper process?

[Cajun Blake]

This video points out the very major difference in what many people consider is trueing an action; the cutting of the action threads.

Many GS's simply run a tap through the existing action threads, square the action face and bolt face etc.This really does nothing to true the threads of the action, it simply cleans up the threads and leaves them with the same amount of misalignment to the bore that the factory rifle came with.

Perfect alignment and single tool cutting the action thread oversized in alignment with the centerline is what should be done.

So when a GS tells you he is Trueing or Blueprinting the action or when you are buying a used rifle that has been Blueprinted how do you know exactly what has or has not been left out of the proper process?

that's why I always ask the GS what exactly is he doing to my action, please explain in detail every step of the way

is he chasing threads w/ a tap, or single point cutting based on center of bore axis

I've done this for so long I know which GS's I trust to work on my rifles.

I rarely buy 700's anymore, pretty much everything I own is built on custom actions.

[bboswell]

that's why I always ask the GS what exactly is he doing to my action, please explain in detail every step of the way



is he chasing threads w/ a tap, or single point cutting based on center of bore axis



I've done this for so long I know which GS's I trust to work on my rifles.



I rarely buy 700's anymore, pretty much everything I own is built on custom actions.

I guess this is exactly my point Blake. I have in the past and I expect many people ask and are told the action is blueprinted and take for granted that it truly is.

[Stick1]

True "blueprinting" goes a whole lot further than most people think, and "truing" can mean several different things depending on who you ask. For me, truing is re-cutting the action threads to run concentric to the centerline of the action and correcting all of the 90 degree surfaces on the front end of the action to be.......well, 90 degrees and make 100% contact with their respective mating surfaces. This would include the action face, the bolt lugs, the bolt lug abutments, bolt face and recoil lug. Yes, I said recoil lug. Technically it is not part of the action I know, but it can throw off everything you have just done to "true" the action if it is not as "square" as everything else in the chain of components. A quick trip to the surface grinder is a good insurance policy to prevent that.

All of that is just the starting point when talking "blueprinting". The bolt itself plays a bigger role in the process than some might think. On a truly blueprinted action I would expect the firing pin hole to be re-bored to dead center and bushed, a new bolt shroud machined and fitted to address play between sear/cocking piece, firing pin travel properly timed and the bolt body sleeved to address the slop/misalignment between it and the raceway. True blueprinting is not seen often outside of rifles built specifically for competition. With all of the great custom actions we have available now, you don't see many 700's running in those circles anyway.

As far as taps go in the truing process, not all are created equal. I'm a believer in single point cutting as it is the way I was taught and has served me well. I also get the fact that a tap will follow the path of least resistance, as I spend a good portion of every day cleaning up after taps that did just that. That said, a tap that is supported by a mandrel and held rigid at both ends can overcome some of those issues. We have been testing a set up just like that recently and it has hung right in there with the single point method when it comes to runout. It probably has it's limits in how much it can overcome I'm sure, but I am now convinced that it is a workable option in most situations if done correctly. The biggest negative we found was tool life, so its not a real attractive option for us, but it may work for some folks.

[savin yours]

Great thread! I should have asked this a long time ago.

[basskicker24]

Tagged for later. Thanks for the info!